The invention relates generally to the development of latent images. Of particular interest to the invention are a method and arrangement for the development of photographic images and, concomitantly, a method and arrangement for the treatment of the fluids discharged in photographic development processes.
From the German Pat. No. 1,188,822 corresponding to U.S. Pat. No. 3,463,711 it is known to continuously regenerate the fixing bath fluid used in a photographic development process by electrolytically recovering silver from the fixing fluid. The article to be fixed is immersed in the fixing bath, which latter is accommodated in a treatment vessel. The electrolytic recovery of silver is carried out in a supply vessel connected with the treatment vessel and the fixing fluid flows through the supply vessel. The intensity or duration of the electrolytic treatment is regulated in accordace with the quantity of photographic material which is passed through the treatment vessel.
The continuous removal of silver from the fixing fluid has the advantage that the fixing bath fluid practically never requires renewal since it constantly maintains its chemical activity. The process of removing silver from the fixing fluid simultaneously serves for chemically regenerating the latter.
The German Pat. No. 1,188,822 does not disclose that developer present on the articles to be immersed in the fixing bath is removed prior to such immersion and the above-described manner of recovering silver has not achieved any practical significance. The quantities of developer conveyed into the fixing bath by the articles immersed therein greatly increase the difficulty of the electrolytic regeneration if not, in fact, making this impossible.
Aside from the above problem, there exists the further problem that the fluids discharged in photographic development processes are chemically aggressive, at least to some extent. This leads to difficulties insofar as environmental pollution is concerned, particularly in view of the ever stricter requirements being imposed on the materials discharged into waterways.
It will be appreciated that improvements in the state of the art are desirable.